Protozoa Flashcards
single-celled eukaryotes (organisms whose cells have
nuclei) that commonly show characteristics usually
associated with animals, most notably mobility and
heterotrophy
Protozoa
move by means of locomotory organelles that arise from
the _____
ectoplasm
locomotory organelle or parasitic amoeba
Pseudopods
only pathogenic amoeba
Entamoeba histolytica
pathogenic and free-living protozoa
- Naegleria fowleri
- Acanthamoeba spp.
- Balamuthia mandillaris
protozoa named by Schaudin
Entamoeba histolytica
progressive motility with hyaline, fingerlike
pseudopods
-rapid progressive undirectinal
Entamoeba histolytica
karyosome: small, central and delicate nuclear
karyosomal chromatin
Entamoeba histolytica
Stages of development for protozoa
Trophozoites and cysts
peripheral chromatin: fine, evenly distributed peripheral chromatin
Entamoeba histolytica
Entamoeba histolytica inclusions (troph)
- Ingested red blood cell
- Charcot-Leyden crystals
-Charcot-Leyden crystals stained with trichrome stain)
bright red
karyosome of E. histolytica
Small and central
Entamoeba histolytica inclusions (cyst)
chromatoidal bars: cigar shaped
chromatoidal bodies on trichrome: bright red
C.bodies in iodine: do not stain
-Diffuse glycogen mass in trichrome is colorless
MOT of Entamoeba histolytica
: ingestion of food or water contaminated by
cysts of the organism
feeding stage
motile
liquid watery stools
not stained by Iodine
Trophozoite
nonfeeding, nonmotile, formed stool
stained by iodine
Cyst
Amoeba that are not intestinal dwellers
E. gingivalis (mouth)
Acanthamoeba
Naegleria
amoeba that does not undergo encystation
E. gingivalis
infective stage of amoeba
cysts
diagnostic stage
cyst and troph
infections by E. histolytica
Liver abscess
Amoebic pericarditis
cutaneous amoebiasis
genital amoebiasis
caharacteristic of intestinal amoebiasis of E. histolytica
FLASK SHAPE ULCER
ANCHOVY SAUCE LIKE
liver abscess in E. histolytica
B. VIRULENT FACTORS of E. histolytica
- Gal/Gal Nac lectin: cytoadherence
- Amebapores: poreformers
- Cysteine proteinase: tissue invasiveness
lab diagnosis of E. histolytica
- Direct Fecal Smear
- Liver aspiration biopsy
- Culture – Non-nutrient agar seeded with E. coli
- Serologic test (SREHP)
- Concentration test
- Radiographic non-invasive techniques:
X-ray/MRI/CT scan
stain for troph
Quensel’s methylene blue
Stains for troph and cyst
Best carmine stain
trichrome stain
Iron hematoxylin stain
what to do if e first examination is negative.
If possible,
three specimens passed at intervals of 2-3 days
should be examined.
Good preservation of morphology of protozoan
trophozoites and cysts
• Easy preparation of permanent stained smears
Schauddinn’s fixative
Iodine and concentration techniques destroy
Trophozoites
Stool must be transported in the laboratory in room
temperature within
1 hour
is an
environment-friendly stool preservative that is useful for
amebic trophozoites
SAF (Sodium acetate-Acetic Acid-Formalin)
Lugol’s iodine
cyst diagnosis
sluggish, nonprogressive motility
Entamoeba coli
Entamoeba coli karyosome
eccentrically located
Entamoeba coli inclusion
vacuole containing bacteria
witch broom stick appearance of diffuse glycogen mass
nuclei of Entamoeba coli cysts
1 - 8
E. histolytica cyst nuclei
1 - 4
nonprogressive motility
E. hartmanni